Being forced to live in a harsh environment makes people find disgusting things less offensive says a St Andrews University researcher.
Professor David Perrett of St Andrews said the study was the first to provide evidence that sensitivity to things that could potentially make you ill, like mouldy food, can be suppressed “in a matter of days” as a survival strategy.
There is already anecdotal evidence of humans overcoming feelings of disgust to survive in extreme circumstances, for example cannibalism following the Andes plane crash portrayed in the film Alive.
“While there is anecdotal evidence that at times of need disgust can be temporarily suspended in order to fulfil more immediate goals, this is the first study to provide evidence that in a matter of days, our disgust sensitivity can be supressed in order to better cope with our current circumstances,” said Dr Perrett.
The study was published this week in the journal Cognition and Emotion.
Researchers Dr Carlota Batres, now of Franklin and Marshal College in the US, and Professor Perrett, repeatedly tested students whose environment did not change as well as student cadets undergoing intensive training at an army camp.
For the students in the stable environment, disgust levels remained constant. At the army camp, the cadets reported increased levels of stress, physical strain, mental pressure and pain.
For these cadets, the harsh training environment was accompanied by a decrease in disgust sensitivity.
After just three days in the training camp, the cadets found concepts like “seeing some mould on old leftovers in your refrigerator” less disgusting, despite not experiencing wounds, cockroaches, mouldy food or even increased levels of hunger. Other forms of disgust, such as disgust for immoral behaviours, remained unchanged.
Lead researcher Dr Batres said: “Pathogen disgust sensitivity decreased from the start of the training camp and then remained constant at the lower level for the duration of the training camp, while the environment remained harsh.
“This suggests that in a harsh environment, where survival may be more difficult, pathogen disgust sensitivity may decrease to allow the consumption of available resources.”